The present invention relates to novel coupling compounds for use as additives in various filled or reinforced polymer resin compositions.
Fillers are generally used in polymer resin compositions as low cost extenders or pigments. They also serve to impart stiffness to molded polymer products. However, the benefits derived from incorporation of fillers are usually offset by corresponding detrimental decreaseas in many properties such as impact strength and melt flow rates. A coupling agent i.e. a compound that can form a mechanical and/or chemical bond between the filler and the resin, is therefore included in the polymer-filler composition to improve these properties. Coupling agents are also used to improve the bond between reinforcing fibers and a resin. In the past nearly all such coupling agents have been organosilanes. Other recently developed coupling agents are those containing titanium including various titanates and titanocenes, as well as other metallocenes e.g. zirconocenes and hafnocenes.
In this application the term "filler" is defined to include conventional fillers as well as reinforcing fibers.